1. Field of the Invention
The present invention relates to an inkjet printer, more particularly, to an inkjet printer improving a printing speed with an ink cartridge having an increased number of nozzles and a method therefor.
2. Discussion of Related Art
Generally, an inkjet printer is a device of receiving electrical signals and outputting ink to print the data on paper, and is equipped with one or two ink heads.
In conjunction with FIG. 1, the conventional inkjet printer 10 can be described as follows. The mounting frame 11 is formed vertically, and side walls 12 and 12' are formed on the right and left of frame 11, respectively. A guide rod 14 connects side wall 12 with side wall 12' and a part 13, for preventing the separation of a carriage 41 during reciprocation, is on the upper side of frame 11. In addition, carriage 41 is installed to be able to reciprocally move along guide rod 14 and part 13, and a timing belt 42 is installed to reciprocally drive carriage 41 along guide rod 14. A feed roller 31 is installed to feed and discharge the paper in the lower part of the frame 11, and a motor 43 is installed to drive timing belt 42 in the back side of frame 11.
The feed roller 31 moves paper in incremental steps in the LF direction (the discharging, or line feeding, direction of the paper) and prints one line per step. When the resolution is 300 dpi, the number of valid pixels in one line is 2550, and 2550 pieces of binary data are printed. Here, as 1 dot is printed at a time, one line is printed when the carriage moves 2550 steps in the CR (carriage return) direction.
The time required to print one line of information is determined by the number of steps necessary for moving the carriage 41 in the CR direction and for moving the paper in the LF direction according to the print resolution, and the printing speed of the ink head. That is, in order to print fast, the print resolution has to be dropped. And in order to raise the resolution and to get a resolution of high quality, more printing time will be required.
Accordingly, it is known that the time for printing one line is as follows:
(1) the number of the carriage moving steps into the CR direction x the time required in order to move the carriage one step (2550 steps on the criterion of 300 dpi); PA1 (2) (2550 times on the criterion of 300 dpi).times.time required in order for the nozzle to jet ink; and PA1 (1) By reducing the number of the steps required for the carriage to move in the CR direction in order to print one line; and PA1 (2) By reducing the number of times the ink head needs to jet ink by increasing the number of nozzles in the ink head.
(3) the time required in order to print one line=(1) +(2).
As shown in the above, in order to print one line, a lot of time is required however fast the printer moves because of the number of times required for repeating each operation. I have determined a method for reducing the printing time, as follows:
That is, there are two methods for reducing the printing time as explained in the above. But the existing device and method cannot perform (1) and (2). Explained more in detail, the printing speed is slow in case of the conventional device and method therefor, and my method for reducing the printing time by increasing the printing speed will been described in detail below.